Every monster is a different key, fitted for the lock we put on our secret selves.

The werewolf — caught up in a brutalizing change he can’t control or remember, fated to hurt most those he loves — unleashes painfully familiar feelings for anyone lost in addiction. The zombie — mindless, motiveless, shuffling endlessly toward some forgotten goal — releases our most modern worries about life without identity, without individuality, without purpose.

Because this monster speaks, solely and frankly, about love and lust and sex, and how that hunger drives him and how that thirst is never slaked — and those are the subjects we work the hardest to hide.

Yet lately, vampire movies have hid them even deeper.

“Dark Shadows,” this Friday’s bloodsucking drama, embraces those obsessions, at first. Its preface sets out a love triangle, its sharp corners pointing to Barnabas Collins, his innocent love, Josette, and the scorned servant girl, Angelique.

Fatefully, Angelique knows something of the dark arts. And so the spurned witch soon sends Josette to her death — and sentences Barnabas to a living death as a vampire, chained in a casket, imprisoned within her own furious heart.

This is a passionate, nearly operatic tale — but too passionate, apparently, for director Tim Burton and star Johnny Depp. Because once that prologue is over, the film shifts in tone, adding sex jokes and smirking camp, replacing melodrama with mockery.

Perhaps tragic, tearful romance only worked when the original “Dark Shadows” was on TV, back in the days of Zeffirelli’s gauzy “Romeo and Juliet” and Erich Segal’s shameless “Love Story.” Perhaps we’re all too controlled now, too jaded, too steeped in irony to believe in that kind of grand, doomed desire.

But what’s truly changed now is that the creatures who used to stand for passion unleashed now stand for passion contained. And our nightmares — and daydreams — are the more anemic for it.

"Nosferatu" (1922), starring Max Schreck.

A gaslit horror

Contagious diseases and female sexuality, secret societies and nefarious foreign influences — these were the love-and-war worries of the Victorian age. And they were the fears that gave us the first great vampire character, 1897’s “Dracula.”

Its Irish author, Bram Stoker, personal assistant to stage star Sir Henry Irving, knew what it was to be at the beck and call of a powerful, charismatic figure. He’d also witnessed — as a loyal friend of Oscar Wilde — the spectacle of a notorious gentleman driven by illegal passion and reduced to secret, hasty assignations.

Both men’s characters played a part in the Count.

So, too, did the 19th-century worries about tuberculosis and syphilis, and the psychological puzzle of, as a frustrated Freud once put it, “What does a woman want?” In 1897, the obvious answers — legal equality, sexual satisfaction — were too shocking for society to acknowledge. And so doctors diagnosed unhappy female patients with “hysteria.”

These social issues played into the character, too — and helped make Dracula a monster for his age.

For ours as well. Because Stoker not only created a best-seller but a new vampire archetype, a courtly villain a world away from the poor, ill-smelling parasites who once haunted folk tales. Privately educated, dressed for dinner, the vampire was remade for the English, upper-class world where your public face was all.

And when he reached the movies, filmmakers added their own culture’s obsessions.

Lugosi’s portrayal stuck — not only to him but to the movies’ idea of what a vampire was. From then on, he was Old World, slightly mocking, endlessly charming. He was, in every way, superior to the dolts opposing him. If English mystery novels were “snobbery with violence,” then Hollywood vampire films were now snobbery with fangs.

The romantic angle, though, began to lessen during the 1940s.

Perhaps it was because the actors now playing the undead — Lon Chaney Jr., John Carradine — were so markedly un-erotic. Perhaps it was because an America at war had less interest in films about powerful passionate foreigners. But the vampires’ interest in female co-stars now became purely practical, as the creatures searched only for the minions they could most easily mesmerize and control.

The stories continued to be told — “Son of Dracula,” “House of Dracula.” But they were bloodless.

David Bowie and Catherine Deneuve in "The Hunger" (1983)

Transfusion of terror

According to legend, the vampire must rest in a coffin lined with his native earth. Fittingly, it took a return to English soil for the genre to be revived as well.

The English “Horror of Dracula,” in 1958, introduced Christopher Lee’s portrayal of the count — and restored physicality to the monster. Lee would dominate the role for another 15 years. The towering actor would also dominate everyone else on screen, as he strode down castle corridors and tossed whimpering villagers aside like weightless rubbish.

Yet while these new movies also added lust to the story — with the vampire’s female victims waiting expectantly in bed, looking hungrily to their open windows — it was strictly one-sided. Lee’s Dracula has no lost love, no true new obsession. Blood and power — these are his real needs. Unswerving and insatiable, he is the ultimate consumer.

In these revolutionary tales, it is the women who are impassioned, their eyes closing in rapture as fangs puncture their flesh. Yet this is yet another sexual revolution that brings freedom without equality; power still remains with the footloose male. Once the act is finished, Dracula is off to the next neck; it’s the women who are left behind to greet the dawn and the frequently ugly consequences.

Predictably, the feminist 1970s brought a brief, albeit bustling sub-genre of vampire films centered more on the women’s point of view. At first, these were really aimed at prurient men — the films’ lesbian vampires tended to be played by imported starlets, their preferred target moving from bared throat to fulsome bosom. And, in the end, it still usually fell to some grim patriarch to restore order with a phallic stake, or sword.

But in some more ambitious films — 1971’s “Daughters of Darkness,” 1983’s “The Hunger” — a subtler, more sophisticated approach began to appear. These older women were monsters, but they had a weary and melancholy maturity; they well knew where every relationship would inevitably lead. You either killed the person you loved, or she became the thing you hate. There were no happy endings.

This gloomy theme had already begun to appear in more traditional vampire stories, which papered over their low-budget flaws with rich melodrama. In these films — “House of Dark Shadows,” “Blacula” — reincarnation often played a role, as the monster strove to recapture a long-dead love. Less villains than anti-heroes, these vampires despised their curse and searched more for true love than fresh blood.

Unfortunately, the latter was always easier to find.

Shadows and mirrors

Sadly, that satisfyingly romantic, truly Gothic sort of love story seems to have gone out of fashion.

Since the 1980s, bloodsuckers are far likelier to be biker trash (“Near Dark”) or beach bums (“The Lost Boys”) than witty charmers; for every “Interview With the Vampire” there are far too many like “Bloodrayne,” “Blade,” “Thirty Days of Night” and “Priest” in which the bloodsuckers are, like Nosferatu’s rats, simply vermin in need of extermination.

The “Twilight” saga brought romance back to the equation, but with a twist; in its fevered stories, it’s the young woman who craves the reluctant vampire’s kiss; it’s the vampire who fights to resist her advances, even going into self-exile in order to put the safety of distance between them. It was both a revival of the Victorian vampire story and a reversed reflection of it.

Yes, like “Dracula,” “Twilight” sees men as uncivilized and sex as dangerous (although rather than presenting a gruesome parable about the dangers of venereal disease, it simply preaches chastity). Yet in “Twilight,” it’s the woman who holds the real power, in “Twilight,” it’s the supposed victim who’s really in control.

With its mix of promise-ring denial and female power, the “Twilight” saga has a more complicated message than some of its critics would allow; like TV’s “True Blood” (which occasionally uses its vampire characters as sympathetic stand-ins for the gay minority), it’s very much a creation of its time. As all vampire films are.

But it’s hard not to miss another time in cinema’s long-ago — and, in retrospect, oddly romantic — 1970s.

When Byronic men with smoldering eyes and Inverness capes wandered the clifftops, staring out at the sea. When a young woman’s mere resemblance to an old portrait could bring back painful memories and desperate hopes. When a vampire’s tale was not just about the undead but the unloved, and their frantic efforts to recapture the one person who had — once — loved them as they were.

And when the greatest fear they evoked was not that they were unlike us, but that we might one day be like them — trapped forever in a prison of our own regret.